Illinois Gov. JB Pritzker on Wednesday will announce a new statewide mask mandate for schools and mandatory vaccinations for employees within some state facilities like prisons and veterans’ homes, multiple sources have confirmed to WBEZ.

The moves aim to address skyrocketing COVID-19 cases fueled by the more contagious delta variant. New coronavirus cases statewide have increased nearly sixfold within the past four weeks, state public health data show.

In terms of the pandemic, the summer had been relatively tranquil in Illinois, with nearly three in four residents having gotten at least one dose of the vaccine and 51% of all Illinoisans — or more than 6.5 million people — being fully vaccinated, state data show.

But with new vaccinations trailing off and the delta variant taking hold, new case counts have jumped and created a dilemma for public school systems across the state. Many of those districts are due to open later this month with partially unvaccinated enrollments, particularly in elementary and middle schools.

Confronted with the new delta variant, the federal Centers for Disease Control & Prevention did an about-face on its guidance for indoor masking in late July. In May, the federal public health agency had said vaccinated individuals didn’t have to wear masks indoors, but those recommendations changed as new cases jumped nationwide.

Pritzker’s moves, which he will outline at a 2:30 p.m. press conference Wednesday that WBEZ will carry live, are being driven by that shifting CDC guidance and the state’s increasing COVID-19 caseload in recent weeks, sources told WBEZ.

Some school districts weren’t adhering to the CDC guidance after facing intense community blowback on requiring students to wear masks. The new orders coming from Springfield will enable school boards wary of that controversy to shift blame to state government.

The state logged nearly 2,700 new COVID-19 cases as of Tuesday compared to 462 on July 7.

Similarly, coronavirus-related hospitalizations across the state are rising. More than 1,100 people were hospitalized with COVID-19 as of Tuesday compared to 423 on July 7, state data shows.

Like other states, Illinois also has seen a handful of breakthrough COVID-19 cases among those who have been vaccinated.

As of July 28, state data show 644 vaccinated Illinoisans had been hospitalized with COVID-19, and 169 vaccinated people have died since January from the coronavirus. Vaccinated COVID patients currently in hospital beds represent an infinitesimal subset – .00009 percent – of the 6.5 million now fully vaccinated.

Dave McKinney covers Illinois government and politics for WBEZ. Follow him on Twitter @davemckinney.